The invention relates to a method for the operation of typewriters, printers or comparable office machines, comprising a control unit including at least one microprocessor, a memory containing the control program, in particular a ROM, and a RAM for storing variable data with at least a part of the storage area being of the value-preserving type, a stepping motor to which the control unit can apply appropriate energizing pattern sequences to change the vertical position of the paper, and a basic-step inputting device which acts upon the stepping motor via the control unit so that, by its actuation, the stepping motor moves the paper by a fraction of a line spacing by executing at least one motor step.
The basic-step inputting device in such office machines serves the purpose of moving the line pattern, which is set choosing one of a plurality of interline spaces, relative to the paper by fractions of a line spacing, in order to be able to type at a precisely given position, e.g., when filling out a form or when setting up a table, a resolution of 16 basic steps typically being possible between two lines of normal typing. When subsequently depressing the normal line-spacing key, the shifted condition remains intact.
In conventional office machines of this type, after an interruption in the typing of a form, a preset energizing pattern is applied to the stepping motor upon restarting the machine, whereby the fine adjustment, made by means of a basic-step key device, for the form just being worked on is lost because, in the majority of cases, the preset energization pattern is not the same as the energization pattern applied to the stepping motor after the actuation of the basic-step key after each complete line spacing. Thus, the completion of a form could not be continued in such a manner that the spaces meant to be filled were actually occupied.